Objectives To evaluate currently used radiopaque agents in a wedge catheter system as a means of achieving parenchymal damage in a variety of endocrine tumors. Methods Employed Prolonged straining of parathyroid adenomas following injection of moderate doses of contrast material through a wedge catheter system has led to permanent control of hyperparathyroidism in a small number of clinical subjects. We are investigating in laboratory animals the potential for using this wedge catheter system to permanently ablate organ function without the use of particulate embolizing agents or plastics. Balloon catheters are used to obstruct arteries into which undiluted contrast material is perfused into the vascular bed of the target organ.